TOWER BRIDGE, London, 78, 327; see the two illustrations facing pages 80 and 328. TRAJAN’S BRIDGE over the Danube, 129-30. TRAJAN’S BRIDGE over the Tagus, 183-7, 309. TREASURY OF ATREUS at Mycenae, 158-9. TREE-BRIDGES, 3, 4, 58, 114, 115-19, 122, 123; tree-bridges with stone piers, 129-32; tree-bridges with timber piles, 133-5. TREZZO BRIDGE, destroyed by Carmagnola, 309-10. TRIANGULAR ARCHES, 157, 160-1. TRIANGULAR BRIDGE at Crowland, see “Crowland”; in Spain, 181. TRIER BRIDGE over the Moselle, with her shrines, 247. TRINITÀ at Florence, 316-17. _TRINODA NECESSITAS_, and its relation to bridges and roads, 40 _et seq._ TRIUMPHAL ARCHES, Roman, on the Pont Flavien at Saint-Chamas, 176; on the bridge at Saintes, 301, and _footnote_; on a Chinese bridge described by Gauthey, 315. TRIUMPHALIS, PONS, 197. TRUTH differs from fact, 11. TRUTHS, TECHNICAL, in Bridge-building, 13. TUDELA BRIDGE, Spain, 285 _footnote_. TUNNELS bored under water by ants, 122; tunnels to displace many of those strategical bridges which airships and aeroplanes could wreck with bombs, 59, 358. TURNER, J. M. W., his “Walton Bridges,” 6. TURNPIKE ACT OF 1773, 59. TURKISH BRIDGE at Zakho, 65-6. TWIZEL BRIDGE and Flodden Field, 94. ULLOA, ANTONIO DE, Spanish Admiral and traveller, _b._ 1716--_d._ 1795, his book on South America; primitive timber bridges, 135; the tarabita, a Peruvian suspension bridge, 146; the fifth Ynca’s bridge of rushes, 146-7; bujuco bridges, 147-8. UNITED STATES OF AMERICA, 142-3, 352-4. UZÈS, on the road to Nîmes, the Pont Saint-Nicolas, XIII century, 295-6. VAISON, in Vaucluse, an important Roman bridge at, 176. VALENTRÉ, PONT, at Cahors, famous war-bridge, 27, 263-4, 282-5, and two illustrations. VATICANUS, PONS, 197. VAUXHALL BRIDGE, London, date and cost, 357. VECCHIO, PONTE, Florence, 210, 222. VENICE, the Rialto, 209, 211-12, and the picture facing page 212; Ponte della Paglia, the picture facing page 152; a canal bridge, 329. VERONA. The fine Veronese bridges are not mentioned in this monograph; they passed from the text in a revision; but pontists know them well, and set great store by the charming Ponte di Pietra, and by the old sloping bridge with forked battlements that swaggers picturesquely across the Adige from the Castel Vecchio. The Ponte di Pietra rises from ancient foundations and she still retains two Roman arches, certainly often restored; the other spans are gracefully architectural. A circular bay for the relief of floods tunnels the spandrils above the cutwater of the middle pier. VICENZA, two bridges of Roman origin, 199.